Seagrasses are underwater plants that form lush meadows in shallow coastal waters.
They are often overlooked and undervalued, but they provide many benefits to people and nature, such as filtering water, stabilizing sediments, protecting shorelines, supporting fisheries and storing carbon.
A new study led by researchers from the University of Michigan has estimated the economic value of the ecosystem services provided by seagrasses in the Caribbean region, as well as the potential of seagrasses to generate income through carbon markets.
The study, published in the journal Biology Letters, is the first of its kind to quantify the natural capital of seagrasses in the Caribbean.
Seagrasses in the Caribbean: a global hotspot
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The researchers used satellite data from the Global Seagrass Watch to map the distribution and extent of seagrass meadows across the Caribbean, as per Phys.org.
They found that the Caribbean contains up to 50% of the world's seagrass area, covering about 550,000 square kilometers.
The Bahamas has the largest share of Caribbean seagrass (61%), followed by Cuba (12%) and Mexico (5%).
The researchers also estimated the amount of carbon stored in seagrass meadows in the Caribbean, using data from previous studies and a global model.
They found that Caribbean seagrasses store about 2.5 billion tonnes of carbon, equivalent to 9.2 billion tonnes of carbon dioxide.
This represents about 33% of the global seagrass carbon stock.
Seagrasses in the Caribbean: a valuable asset
The researchers then calculated the economic value of the ecosystem services provided by seagrasses in the Caribbean, using existing valuation studies and benefit transfer methods, as per the University of Michigan.
They considered four categories of services: climate regulation (carbon storage and sequestration), coastal protection (wave attenuation and erosion control), habitat provision (nursery and refuge for marine life) and food provision (fisheries support).
They found that Caribbean seagrasses provide about $255 billion in services to society annually, including $88.3 billion in climate regulation, $83.9 billion in coastal protection, $41.4 billion in habitat provision and $41.3 billion in food provision.
The Bahamas alone receives total ecosystem services valued at $156 billion annually, including $54 billion in climate regulation, $52 billion in coastal protection, $25 billion in habitat provision and $25 billion in food provision.
The researchers also explored the potential of seagrasses to generate income through carbon markets, which could provide incentives for conservation and restoration.
They estimated that if 10% of the seagrass carbon stock in the Caribbean were sold as blue carbon credits at a price of $10 per tonne of carbon dioxide equivalent, it could generate $9.2 billion in revenue.
Seagrasses in the Caribbean: a threatened treasure
The researchers concluded that seagrass ecosystems in the Caribbean are of global importance and provide substantial benefits to society.
However, they also warned that seagrasses are facing multiple threats from human activities, such as coastal development, pollution, overfishing and climate change.
These threats could reduce the extent and quality of seagrass meadows, as well as their capacity to store carbon and provide other services.
The researchers recommended that seagrass conservation and restoration should be prioritized in the global agenda, and that blue carbon markets could be a promising tool to support these efforts.
They also called for more research and monitoring to improve the understanding and valuation of seagrass ecosystems in the Caribbean and elsewhere.
